1. Field of the Invention
The present invention relates to the field of thoracic surgery. In particular, the invention relates to an improved rib retractor for use in thoracic surgery, e.g., coronary artery bypass or mitral valve replacement surgery and the like.
2. Background Art
Various retractors for maintaining access to thoracotomy incisions such as, e.g., the Finochietto rib retractors are known in the art. Likewise, retractors for use in sternotomy incisions are also known in the art. U.S. Pat. No. 4,852,552, for example, discloses a sternal retractor for use in internal mammary artery surgery. Generally, such rib retractors or sternotomy retractors are comprised of two substantially perpendicular retractor blades which remain generally perpendicular in their operative or deployed position. This substantially perpendicular orientation of the blades limits the surgeons mobility and access to the surgical field. This is especially true for procedures that are performed deep within the thoracic cavity.
Often, the retractor blades are fenestrated or open over at least a portion of their surface area and are not contoured for an "anatomical fit" against the rib. Such a design concentrates pressure and often results in increased trauma to the intercostal veins, arteries, nerves and musculature. Fenestrated or open blades likewise increase trauma because the intercostal tissue, under pressure, tends to be extruded through the openings, thereby incurring damage via the sharp edges of the blade openings or via blunt trauma resulting from contact with instruments during the procedure. This fenestrated blade design also reduces the surgical field due to tissue impingement and can increase hemorrhage at the incision site making it more difficult for the surgeon to visualize deeper structures.
In order to increase the surgeons access to the surgical field, standard Finochietto retractors have been limited to a single ratcheting mechanism which is attached to the retractor blade via a substantially perpendicular retractor arm. This design attempts to create a window or space between the rachet and retractor blade where the surgeon can access the surgical site. However, such an arrangement often results in unequal distribution of force and, actually, can increase the total amount of force necessary to maintain adequate adduction of the ribs for access to the surgical site.
Prior to the present invention, there has not been a retractor designed especially for the narrow window presented via an intercostal thoracotomy approach which overcomes the above disadvantages of the prior art. Prior to the present invention there existed a need in the art for a rib retractor which would provide increased surgical access field with an increased range of motion for the long shafted surgical instruments that are often utilized deep within the thoracotomy, especially with cardiac procedures. There also exists a need for a retractor which uniformly distributes force over the retractor blade area and which minimizes trauma to the intercostal tissue.